Regulating system



Aug. 11, 1953 s. L. BRADLEY 2,648,813

REGULATING SYSTEM Filed March 14, 1951 2 Shets-Sheet 1 WITNESSES:

- INVENTOR Amperes F lg. 2.

| l 3;; um 7 ATTORNEY Schuyler L. 1 Bradley.

A118. 1953 s. L. BRADLEY 2,648,813

Y REGULATING SYSTEM Filed March 14, 1951 2 Sheets-Sheet 2 Patented Aug.11, 1953 UNZI'FE D PATENT OFFICE REGULATING SYSTEM Schuyler- L. Bradley,Pittsburgh, Pa., assignor t'o Westinghouse Electric Corporation, EastPittsburgh, Pa a corporation of Pennsylvania Applibation'Marchll, 1951,Serial N0. 215,547-

3 Claims. 1,

This invention relates to regulating systems and particularly',. toregulating system's embodying. a voltage referencerietwork.

Regulating systemshave been utilized which embodied voltage referencenetworks for detect ing. a departure of the" output voltage ofagenerator from its regulated value, and the output of such networkshave been amplified and used to eifect a changein the excitation ofthegenerator to return the output voltage of the generator to apredetermined value which is to be maintained; However, in theseregulating systems heretofore used; only a small percentage ofthe'power' input to the voltage reference net'- worlc was utilized: inreturning the output voltage of the generator to its regulated value.

The lossof power caused by the inefficient voltage. reference networkincreased the initial cost' of the regulating'.syst'em since it wasnecessary to provide large component parts for the regulating. system.

An object of this-invention is the provision of a regulating systemhaving a sensitive voltage reference networkin which a relatively largepercentage of the power input to the voltage reference network is usedin effecting aregulatingaction.

Another object of this invention is the provision in-a' regulatingsystemfor maintaining the output voltage of a generator substantially constantof: a voltage reference network having two non-linear impedance circuitswhich have predetermined voltage-current characteristics, and inwhicha-relatively'large percentage of the power input to the voltagereference networkis utilized in returning the output voltage of thegenerato'r to its regulated value.

Still another object of this invention is the provision of an eflicientvoltage reference network utilizing two non-linear impedance circuitshaving predetermined voltage-current characteristics.

Other objects of this invention will become apparent from the followingdescription when takenin conjunction: with the accompanying drawings, inwhich;

Figures 1A and 1B- are composite diagrammatic'representations'ofapparatus and circuits embodying the teachings ofthisinventicn, and

Fig. 2 is a graph; the'curves of which represent the electricalcharacteristics ofthe two nonlinear impedance circuits utilized in-thesystem Of-t Figs. 11A and-1B.

Referring: to the drawings and, in particular, to Figures 1A and lB-thereof there is illlustr-ated a regulating system utilized formaintaining the output voltage of a generator lflsubstantially constant.The regulating. system comprises} in general, afrequency-compensating-network ['2', a voltage reference network I l"and j amplifier 56 disposed to control the excitation of a regulatinggenerator iii, the output of which is disposed to controlthe excitationof the generator It; In this instance, the generator comprises a fieldwinding- 23 and'arinaturewinli ings 253 connected to supply loadconductors 22, 2d and 2d. The field winding 231'sdisp'o's'e'd to beenergized in accordance with the'output' of a regulating generator [8,the generator i8 illustrated comprising. armature windings (ill: aselfexcited field winding 32", and a pair of opposed control windings 34and 35 In order to provide a measure of the output of the generator 99,the voltage of which is" to be maintained substantially. constant, thefrequency compensator IZ: is connected through a potential transformer33, the primary windings of which are connected across the 15mconductors 22 and'Z l. As willbe understood} many di'f ferent frequencycompensators may be' employed, the frequency compensator in-thisinstance comprising a series-connected compensating reactor Ml and'acapacitor Aland a bank oficapac'itors 52 4 of different size disposed tobe'seiecnvay connectedacross'the circuit by an adjustahl e'coiitactmember 55. Thusthepositio'n of'tlie'co'ntact member 46 for selectivelyconnecting'o'neof the capacitors ti l in circuit depends upon thefrequency of the generator ill which is to Becompensated for. Asillustrated, the frequency'coidpensator iz'is connectedto'tlie secondarywinding of the transformer tdthrough a voltage" divider idfor thepurpose of adjusting the voltage output which is obtained across theoiitputte'rminals 59 and 52 of the compensator.

In order to provide a sensitive measuriiigcircuit for. measuring thedeviationsoi the voltage across the loadconductors 22a'ndZ i; the'vouage reference network l l' is connected to the output terminalsEilan'd 52 of the frequency? compensator l2. The voltage referencenetwork l'ilin" this instance comprises two non-linear impedancecircuits 54 and 56 disposed to supply full-wave dry-type rectifi ers 58'and Eli; respectively. The non-linear impedance circuit 54' comprisesaseries-connected capacitor 62. and a satur'able reactor 64,- whereasthe non-linear impedancecircult 5e comprises a parallel connect'edcapacitor 68 and a-saturable reactor 58 Anisolating transformer iiiisdisposedin the non-linear circuit 56 to isolate the components thereofand the components of the non-linear circuit 56 from the rectifiers 5tand to prevent circulating currents therein. The electricalcharacteristics of the non-linear impedance circuits 54 and 56 will bereferred to and described more fully hereinafter.

In order to provide for obtaining a variable output from the voltagereference network [4 in accordance with the deviation of the voltageacross conductors and 2 from the predetermined value which is to bemaintained substantially constant, the output terminals of therectifiers 58 and t9 are connected in circuit relation with a resistorE2, different portions or sections of which are disposed to be connectedin circuit relation with the respective rectifiers, as by means of asliding contact member M. Thus, the portion ii of the resistor l2connected between the contact member it and one of the output terminalsof the rectifier Bil will provide a potential which is a measure of theoutput of the rectifier 6d, and the portion of the resistor 12 connectedbetween the movable contact member 14 and one of the output terminals ofthe rectifier 58 will provide a potential which is a measure of theoutput of the rectifier 5B. In order to provide for adjusting thepotential across the section 13 of the resistor '52 so as to obtain asubstantially zero net effective potential across the resistor 72,

a movable contact member it is provided for movement for controlling thesize of the portion E3 of the resistor '52 in circuit relation with therectifier 58. By adjusting the position of the contact member iii, a netefiective zero potential may be obtained across the resistor 2 for agiven voltage across load conductors 22 and 24 which is to be maintainedsubstantially constant.

In order to eiiectively amplify the output from the voltage referencenetwork Hi so as to obtain sufiicient power for controlling theexcitation of the regulating generator iii, the magnetic amplifier i6 isconnected in circuit relation between the output terminals l5 and H ofthe voltage reference network Hi and the opposed control field windings34 and 36 of the regulating generator H8. The magnetic amplifier itillustrated comprises four saturable reactors i8, 80, 82 and 34. Each ofthe saturable reactors is provided with an alternating-current winding86, 88, 9t and 92, respectively, connected to supply the control fieldwindings a l and 35. Any suitable source of alterhating-current powersupply may be utilized although in this instance a potential transformer94 is employed, the potential transformer 94 having its primary windingconnected across the load conductors 2d and 26. The transformer 94 isprovided with two secondary windings 9t and 98, the secondary winding 36being disposed to supply the alternating-current windings 8t and 88 ofthe reactors l8 and 8%, respectively, which alternating-current windingsare connected in series circuit relation with each other and areconnected to the input terminals of a dry-type rectifier mi). Likewise,the secondary winding 98 of the transformer El i is connected to supplythe alternatingcurrent windings 9t and 92 of the reactors 82 and 84,respectively, the alternating-current windings til and 92 beingconnected in series circuit relation with one another and in circuitrelation with the input terminals of a dry-type rectifier Hi2. Asillustrated, the output terminals of the rectifiers we and we areconnected to supply the control field windings 3d and 36, respectively,a resistor 504 being connected intermediate an output terminal of therectifier tilt and an output terminal of the rectifier Hi2 and themidpoint of the resistor llll being connected to the control fieldwindings 3t and it. Theselater connections provide a potential dropacross sections I03 and I05 of the resistor EM which is a measure of theexcitation of the control field. windings 34 and 36. The resistor EM isprovided with movable contact members m6 and I98 for adjusting thepotential drop across the sections- IM and I05 of the resistor HM whichare connected in circuit relation with the rectifiers E90 and I02,respectively.

As illustrated, a plurality of direct-current control windings IN, H2,H4 and lit, are pro-- vided on the reactors i8, 30, $32 and 8%,respectively, to control the impedance of the alternat-- ing-currentwindings 86, 883, 9t) and 92, respectively. The control windings lit andH2 are connected in series circuit relation with respect to one another,and the control windings i it and H6 are also connected in seriescircuit relation with respect to each other. However, the seriescircuit-connected windings lit and H2 are connected in parallel relationwith the series circuit connected control windings lid and lit. Thisparallel circuit is connected to input terminals I it and 520, which arein turn connected by conductors I22 and E24 through movable contactmembers 526 and E23, respectively, of a manually operated switch itil,which will be referred to hereinafter, and conductors 32 and ltd,respectively, to the terminals ii and i5, respectively, of the resistorE2 whereby the control windings H6, H2, HQ and H6 are energized inaccordance with the net effective potential across the resistor '52, thedirection of current flow through these windings being dependent uponthe polarity of the net effective potential across the resistor 12.

In addition to the direct-current control windings H6, H2, lid and HE,each of the reactors l8, Bil, 82 and 84 is provided with a biasingdirect current control winding E36, 838, Hit and H52, respectively,which windings likewise serve as feedback windings. The biasing windings531i; and [38 are connected in series circuit relation with one anotherand are connected across section m3 of the resistor 164 so as to beenergized in accordance with the potential across such section and inaccordance with the iiow of current from the rectifier Hit through thecontrol field winding 34 of the regulating generator 58. Likewise, thebiasing windings hit and M2 are connected in series circuit relationwith one another across section I85 of the resistor Wt so as to beenergized in accordance with the potential across such section of theresistor its and in accordance with the flow of current from therectifier m2 through the control field winding 36 of the regulatinggenerator i8. It is to be noted that the biasing windings H36 and 38 areso disposed on the reactors l8 and 8%], respectively, that the fluxproduced by the current fiowing through such biasing windings isadditive to the flux produced by the current flowing through thedirect-current control windings HQ and H2, respectively, when the fluxproduced by the current fiowing through the biasing windings its and M2is at any instance in opposition to the flux produced by the currentflowing through the direct-current control windings i M and HE,respectively, of the reactors 82 and 84, respectively. On the otherhand, when the flux produced by the direct-current control windings Hi)and H2 of the reactor l8 and 86 is in opposition to the flux produced bythe biasing windings I36 and I33, respectively, then it is to be notedthat the flux produced by the current flow through the direct-currentcontrol windings He and iii} of reactors 82 and 84, respectively, isadditive to the flux produced by the current flow through the biasingwindings I and I42, respectively. The polarity of the potential acrossthe resistor I2 of the voltage reference network I4 will determinewhether or not the fluxes of the direct-current control windings III!and II2 or" the reactors i8 and 6! respectively, is additive or inopposition to the flux produced as a result of the energization of thebiasing windings I36 and I66, respectively.

Each of the reactors l8, Bil, 52 and 84 is also provided with a dampingwinding I56, I 46, I48 and I50, respectively, for controlling thesaturation of the reactors in accordance with the rate of change in theexcitation of the generator field winding 25. Thus, the flux resultingfrom the rate of change of the excitation voltage of the generator Ii)wili oppose the flux of the directcurrent control winding associatedtherewith on each of the reactors "I6, 86, 62 and iii. For this purpose,the damping control windings I44, I46, I 48 and I56 are connected inseries circuit relation to be supplied in accordance with the output ofthe regulating generator I8, such control windings being connected tothe output of the regulating generator I8 through a potentialtransformer I52.

As will be appreciated, under certain conditions, it will be desirableto effect a manual regulation of the output of the generator IQ insteadof the automatic regulation, which can be obtained with the regulatingsystem just described. For this purpose, a manual control circuit [5 isprovided, the switch I36 being disposed for operation to disconnect theoutput of the voltage reference network It from the amplifier i6 and toconnect the manual control circuit I54 to the magnetic amplifier. Theswitch I36 comprises a plurality of movable contact members I26, I28,I55, I58, I66 and I62, the contact members I26 and IE8 being disposed incircuit-making position to establish the automatic regulating systemwhen the switch I36 is in the position illustrated. The contact membersI56, I56, i613 and I62 are in the ci cuit-opening position when thecontact member I26 and I23 are in the circuit-closing position. For amanual regulation of the generator Iii, the switch IE6 is actuated so asto move the contact members I26 and I26 to a circuitopening position andthe contact members I through I62 to a circuit-closing position.

The manual control circuit I54 comprises a suitable bridge circuit, theinput terminals I64 and IE5 of which are disposed to be connected acrossthe output circuit of the regulating generator I6 when the switch I36 isin the manual control position. As illustrated, the manual controlcircuit comprises a suitable bridge circuit having four legs, one of thelegs comprising a resistor I66, another leg comprising a pair ofparallel but opposed rectifiers I'iil and I l2, the other legs beingformed of a resistor Il 'i, which has an adjustable contact member I'etdisposed for movement intermediate the ends of the resistor I'M, themovable contact member I16 being connected to an output terminal 578 or"the bridge circuit, the other output terminal I86 of the bridge circuitbeing connected intermediate the legs formed by the resistor I58 and theparallelconnected rectifiers I16 and I12. Thus, with the switch I36disposed for a manual operation of the system, the contact members I56and I58 connect the output terminals I18 and I of the bridge circuit tothe direct-current control windings III], II2, H4 and H5 of the reactorsI3, 86, 82 and 64, respectively, to control the output of the magneticamplifier and thereby control the energization of the generator IIl. Byadjusting the movable contact member I16, the output potential and thepolarity of the manual control bridge I54 can be readily controlledmanually.

Before putting the regulating system embodying the teachings of thisinvention into use, certain adjustments of the apparatus must be made.The movable contact member 46 of the frequencycompensating circuit I2should be adjusted until it completes an electrical circuit to theproper capacitor 44 in order that proper frequency compensation may beobtained. When the proper frequency compensation is obtained, thevoltage input to the voltage reference network I2 will be substantiallyunaffected by changes in frequency of the alternating-current generatorII].

The slidable contact members 56 and 74 of the voltage reference networkI4 are adjusted so that there is no voltage at the output of the voltagereference network I4 when the output voltage from thealternating-current generator I6 is at its regulated value. As regardsthe magnetic amplifier I6, the slidable contact members I66 and I68 areadjusted until the flux produced by the direct current flow through thefield windings 34 and 36 of the generator I6 is in opposition and equalin magnitude when the output voltage from the alternating-currentgenerator I6 is at its regulated value.

The voltage divider 48 should then be adjusted until the voltage inputto the voltage reference network I4 is of such a magnitude that theproper correction voltage can be applied to the field winding 28 of thealternating-current generator ID to thus maintain the output voltage ofthe alternating-current generator It at its regulated value.

In operation, with the switch ldil positioned as shown in Fig. 1A of thedrawings, in which the movable contact members I26 and I26 are in thecircuit closing position and the movable contact members I56 through I62are in the circuit interrupting position, if there is an increase ordecrease in the magnitude of the voltage output of thealternating-current generator Iii from its regulated value, a measure ofthis increase or decrease in voltage will appear across the outputterminals 56 and 52 of the frequencycompensating circuit I2 and thusacross the input to the voltage reference network It. As hereinbeforementioned, the frequency-compensating circuit I2 maintaining the inputvoltage to the voltage reference network I4 is unaifected by thefrequency of the alternating-current generator I0,

Referring to Fig. 2 of the drawings, there is illustrated a graph, thecurves of which represent the electrical characteristics of thenonlinear impedance circuits 54 and 56 utilized in the system shown inFigs. 1A and 1B. Curve I82 represents the magnitude of the current flowthrough the capacitor '66 and the saturating reactor 58 for variousmagnitudes of voltages that are impressed across the input terminals 56and 52 to the voltage reference network I4. Curve I84 represents themagnitude of the current flow through the capacitor 62 and thesaturating reactor 64 for various voltages that are impressed across theinput terminals 50 and 52 to the voltage reference network I4. When thevoltage impressed across the input terminals and 52 to the voltagereference network is has a ma nitude equal to that represented by I86 onthe graph, the current flow through the two nonlinear impedance circuitsM- and 56 will be of equal magnitude. When the current flow throughthese two non-linear impedance circuits is of equal magnitude, theoutput voltage of the alternating-current generator Iii should be at itsregulated value.

As can be seen from Fig. 2 of the drawings, with an increase in theoutput voltage of the alternating-current generator Iii (as representedby I88 on the graph), there will be a wide difference in the magnitudeof the current that is flowing through the impedance circuit 5dcomprising the capacitor 52 and the saturating reactor 64 and theimpedance circuit 56 comprising the capacitor 66 and the saturatingreactor 58. The current flow through the impedance circuit 56 is of asmaller magnitude than the magnitude of the current flow through theimpedance circuit 54 when the output voltage of the alternating-currentgenerator Ill is above its regulated value. A current of smallermagnitude will flow through the portion ii of the resistor l2 that isconnected to one of the output terminals of the rectifier 6i] and theslidable contact member M than will flow through the portion I3 of theresistor '52 that is connected to one of the output terminals of therectifiers 58 and the slidable contact member W. The current flows inopposite directions through the portions ii and T3 of the resistor I2and when the magnitude of the current flowing in these two portions ofthe resistor '52 is not equal, there will be a voltage across theresistor I2. The polarity of this voltage and thus the direction of flowof the current that passes through the resistor '52 to the magneticamplifier It will be determined by which portion of the resistor I2 hasthe greater magnitude of current flowing therethrough.

If the output voltage of the alternating-current generator It risesabove its regulated value, the polarity of the net effective Voltageacross the resistor '52 will be such that the current to the amplifierI6 will flow through the resistor l2 in the direction of the outputterminal l? of the rectifier 59, through the conductor I32, the movablecontact member I26, the conductor I22, the input terminal I I8 of theamplifier it, the parallel circuit comprising the series connectedcontrol windings IIii-I I2 and II iIiI3, the input terminal I29, theconductor I25, movable contact member I28, and conductor 534, to outputterminal I5 of the voltage reference network It. The current flowthrough the biasing windings I36 and I 33 will be in such a directionthat the flux produced thereby will be additive to the flux produced bythe control windings H0 and H2 respectively. However, the flux producedby the direct-current flow through the biasing windings M9 and I62 willbe in opposition to that flux produced by the direct-current flowthrough the control windings IM and lit respectively. When the fluxproduced by the current flow through the control winding I It is equalin magnitude and opposite to that fiux produced by the direct-currentflow through the biasing winding I40 and the flux produced by thedirect-current flow through the control winding I I6 is equal inmagnitude and opposite to the flux produced by the direct-curent flowthrough the biasing winding M2, there will be a minimum of saturation ofthe magnetic core members 82 and 34, the alternating-current windings 9tand 92 then offering a maximum of impedance to the current flow, andthus rendering a minimum of current flow to the field winding 36. Whenthe flux produced by the current flow through the control windings I HIand I It rises to a magnitude that is greater than the magnitude of theflux produced by the current flow through the biasing win-dings [4e andI42 respectively, there will momentarily be a current flow of greatermagnitude through the alternating-current windings 96 and 92 than is thecase when the flux produced by the current flow through the controlwinding II and the biasing winding Me is equal in magnitude. When thecurrent flow through the alternating-current windings 9E] and 92increases momentarily the output current from the rectifier I52 and hencthe current flow through the biasing, windings ME and I 42 increases.This increased current flow in the biasing windings EM) and I52 producesan additional biasing flux to offset and oppose the flux produced by theadditional current flow through the control windings I Hi and Iii; afterthe transition point is passed where the magnitude of the flux producedby the current flow through the control winding i I4 is equal inmagnitude and in opposition to that flux produced by the current flowthrough the biasing winding I66. Therefore, the current flow through thefield winding 35 remains substantially at the same minimum value firstreached even though the flux produced. by the current flow through thecontrol windings IHI and lit increases in magnitude beyond that value atwhich the flux produced by the control windings i I d and I it was firstequal in magnitude to the flux produced by the current flow through thebiasing windings ME and I42, respectively.

Still assuming the output voltage of the generator It is above itsregulated value, with each increase in current flow through the controlwindings Iiil and H2, there is a proportional increase in the total fluxproduced by the current flow through the control windings III! and H2.This increased current flow in the control windings I Ill and H2 furtherincreases the saturation of the magnetic core members l2 and 530,respectively, thus lowering the impedance of the alternatingcurrentwindings 86 and 88, thus increasing the output current of the rectifierHid to the biasing windings I36 and I38. The increased current flowthrough the biasing windings I36 and I33 increases the flux produced bythese windings. Since the fluxes produced by the control windings Iii)and I I2 are additive to the fluxes produced by the biasing windings 36and I33 respectively, the impedance of the alternating-current windingsand 88 is further lowered and the current fiow through the field winding3 of the control generator I8 continues to increase in proportion to thecurrent flow through the control windings I I i] and I I2. Thus thefeedback to the biasing windings I35, I38, ME) and M2 which likewise actas feedback windings, is such as to produce a wide difference in themagnitude of the current flow through the field windings 3d and 36 ofthe generator I8 when the output of the generator If! is not at itsregulated value and therefore a maximum of useful output from themagnetic amplifier IS.

The combined flux produced by the direct-current flow through the fieldwindings 3d and 35 of the control generator I 8 when the output voltagefrom the alternating-current generator It is above its regulated valuecauses the output voltage from the control generator l8 to decrease,thus decreasing the voltage across the field winding 28, lowering theoutput voltage of the alternatingcurrent generator It to its regulatedvalue.

The rapid rise in the flux produced by the current fiow through thecontrol windings H0, H2, H and H5 is opposed by the fiux produced by thecurrent fiow through the damping windings Md, 1%, MB and ISO,respectively. This prevents an overcorrection of the output voltage ofthe alternating-current generator I!) and renders a more stableregulating system.

If, however, the output voltage of the alternating-current generator iiifalls below the regulated value, a measure of the decreased voltage willbe impressed across the input terminals 50 and 52 to the voltagereference network i4. Referring to Fig. 2 of the drawings, it can beseen that when the output voltage of the alternating-current generator iis below the regulated value as represented by Hit, the current flowthrough the nonlinear impedance circuit 54 will be of a smallermagnitude than the magnitude of the current flowing through thenon-linear impedance circuit '6. When this operating condition exists,the current will fiow through the resistor E2 of the voltage referencenetwork it in a direction towards the output terminal 15, through theconductor i34, the movable contact member I28, the conductor I24, theinput terminal 12 of the amplifier IS, the parallel circuit comprisingthe series connected control windings lie-H2 and lid-Hi the inputterminal N3 of the amplifier it, the conductor 22, the movable contactmember H6, and the conductor I32 to the output terminal ll of thevoltage reference network M. The current fiow through the controlwindings it, H2, H4 and H6 is in such a direction that the flux producedby the current flow through the control windings Hi3 and H2 will beopposed to the fiux produced by the direct-current fiow through thebiasing windings H5 and 238, respectively. The current flow through thecontrol windings I it and H6 will be in such a direction that the fiuxproduced thereby will be additive to that fiux produced by the directcurrent flowing through the biasing windings Md and M2, respectively.When the current flows in this manner through these windings of themagnetic amplifier 16, there will be an increase in the current flowthrough the field winding 36 over that value that exists when the outputvoltage of the alternating-current gerberatcr It is at its regulatedvalue.

When the output voltage of the alternatingcurrent generator is below itsregulated value, the flux produced by the current fiow through thecontrol windings H9 and H2 will be in opposition to the flux produced bythe current fiow through the biasing windings I36 and [38, respectively,and the current flowing through the field winding 34 will be decreasedand maintained at a minimum magnitude for reasons as hereinbeforementioned. The combined flux produced by the current flow through thecontrol field windings 3:1 and 33 causes the output voltage of thecontrol generator is to increase to such a value that the output voltageof the alternating-current generator it is raised to its regulatedvalue.

As hereinbeiore mentioned, the output voltage of the alternating-currentgenerator [0 may be manually controlled by means of the manual control54. To switch to manual control, the switch i311 is first actuated so asto move the contact members H6 and I28 to the circuit interruptingposition and the movable contact members I56, I58, I60 and [62 to thecircuitclosing position. With these latter contact members sopositioned, the slidable contact member H6 may be actuated towards oneend or the other of the resistor I74. This efiects an unbalance of themanual control circuit W! or Wheatstone bridge in one direction or theother to either increase or decrease the output voltage of thealternating-current generator [0.

The regulating system embodying the teachings of this invention hasseveral advantages. As hereinbefore mentioned, a large percent of thepower input to the voltage reference network M is utilized inmaintaining the output voltage of the alternating-current generator [0substantially constant. Since a smaller amount of power is required inoperating the regulating system, its size can be considerably decreased.oftentimes, such a decreased size is invaluable when there are spacelimitations.

I claim as my invention:

1. In a regulating system for maintaining an electrical quantitysubstantially constant, the combination comprising, a network disposedto be energized in accordance with the electrical quantity andresponsive to variations therein to produce an output voltage, thepolarity of which depends upon the magnitude of the electrical quantity,the network comprising a first nonlinear impedance circuit and a secondnon-linear impedance circuit disposed to be simultaneously energized inaccordance with the electrical quantity, the first non-linear impedancecircuit comprising a saturating reactor and a capacitor connected inseries circuit relation, the second non-linear impedance circuitcomprising a saturating reactor and a capacitor connected in parallelcircuit relation, a dry type rectifier unit connected to be supplied bythe first non-linear impedance circuit, another dry type rectifier unitconnected to be supplied by the second non-linear impedance circuit,circuit means connected to the output terminals of said dry typerectifier unit and to said another dry type rectifier unit for producingthe output voltage for the network, a magnetic amplifier responsive tothe output Voltage of the network, the magnetic amplifier comprising twopairs of magnetic core members, an alternating-current load windingdisposed .on each of the magnetic core members, two rectifiers of thedry type for rectifying the output of the amplifier, the amplifierrectifiers having input and output terminals, means for connecting thealternating-current windings on one pair of magnetic core members to theinput terminals of one of the amplifier rectifiers and means forconnecting the alternating-current windings on the other pair ofmagnetic core members to the input terminals of the other amplifierrectifier, a control winding disposed on each of the magnetic coremembers, the direction and magnitude of the current flow through thecontrol windings being dependent upon the po larity of the outputvoltage of the network, a biasing winding disposed on each of themagnetic core members, the biasing windings on said one pair of themagnetic core members being responsive to the output of said one of theamplifier rectifiers, the biasing windings disposed on said other pairof the magnetic core members being responsive to the output of saidother amplifier rectifier, and the biasing windings on one pair ofmagnetic core members being so disposed that for a predetermineddirectional output from the network the flux produced by the currentflow through the biasing windings is in magnetic opposition to the fiuxproduced by the current fiow through the control windings on the samepair of magnetic core members while the flux produced by the currentflow through the biasing windings disposed on the other pair of magneticcore members is additive to the flux produced by the current fiowthrough the control windings on the said other pair of magnetic coremembers, and control means responsive to the output of the two amplifierrectifiers for controlling the electrical quantity.

2. In a regulating system for maintaining an electrical quantitysubstantially constant, the combination comprising, a network disposedto be energized in accordance with the electrical quantity andresponsive to variations therein to produce an output voltage, thepolarity of which depends upon the magnitude of the electrical quantity,the network comprising, a first nonlinear impedance circuit and a secondnon-linear impedance circuit disposed to be simultaneously energized inaccordance with the electrical quantity, the first non-linear impedancecircuit comprising a saturating reactor and a capacitor connected inseries circuit relation, the second nonlinear impedance circuitcomprising a saturating reactor and a capacitor connected in parallelcircuit relation, a dry type rectifier unit connected to be supplied bythe first non-linear impedance circuit, another dry type rectifier unitconnected to be supplied by the second non-linear impedance circuit,circuit means connected to the output terminals of said dry typerectifier unit and to said another dry type rectifier unit for producingthe output voltage for the network, a magnetic amplifier responsive tothe output voltage of the network, the magnetic amplifier comprising twopairs of magnetic core members, an r alternating-current load windingdisposed on each of the magnetic core members, two rectifiers of the drytype for rectifying the output of the amplifier, the amplifierrectifiers having input and output terminals, means for connecting thealternating current windings on one pair of magnetic core members to theinput terminals of one of the amplifier rectifiers and means forconnecting the alternating-current windings on the other pair ofmagnetic core members to the input terminals of the other amplifierrectifier, a control winding disposed on each of the magnetic coremembers, the direction and magnitude of the current fiow through thecontrol windings being dependent upon the polarity of the output voltageof the network, a biasing winding disposed on each of the magnetic coremembers, another resistance member connected between an output terminalof one of the amplifier rectifiers and an output terminal of the otheramplifier rectifier, the biasing windings on one pair of magnetic coremembers being connected between one end of said other resistance memberand an intermediate point thereof, the biasing windings on the otherpair of magnetic core members being connected between said intermediatepoint of said other resistance member and its other end, and the biasingwindings on one pair of magnetic core members being so disposed that fora predetermined directional output from the network the flux produced bythe current flow through the biasing windings is in magnetic oppositionto the flux produced by the current fiow through the control windings onthe same pair of magnetic core members when the flux produced by thecurrent flow through the biasing windings disposed on the other pair ofmagnetic core members is additive to the flux produced by the currentflow through the control windings on said other pair of magnetic coremembers, and control means responsive to the output of the two amplifierrectifiers for controlling the electrical quantity.

3. In a regulating system for maintaining the output voltage of analternating-current generator substantially constant, the combinationcomprising, a frequency compensating circuit responsive to the outputvoltage of the alternatingcurrent generator for maintaining the voltageoutput of the frequency compensator circuit substantially constantirrespective of the frequency of the alternating-current generator, anetwork disposed to be energized in accordance with the output of thefrequency compensator circuit to reduce an output voltage, the polarityof which depends upon the magnitude of the output voltage or" saidgenerator, the network comprising a first non-linear impedance circuitand a second non-linear impedance circuit disposed to be simultaneouslyenergized in accordance with the electrical quantity, the firstnon-linear impedance circuit comprisng a saturating reactor and acapacitor connected in series circuit relation, th econd non-linearimpedance circuit compr ing a saturating reactor and a capacitorconnected in parallel circuit relation, a dry type rectifier unitconnected to be supplied by the first non-linear impedance circuit,another dry type rectifier unit connected to be supplied by the secondnon-linear impedance circuit, circuit means connected to the outputterminals of said dry type rectifier unit and to said another dry typerectifier unit for producing the output voltage for the network, amagnetic amplifier responsive to the output voltage of the network, themagnetic amplifier comprising two pairs of magnetic core members, analternating-current load winding disposed on each of the magnetic coremembers, two rectifiers of the dry type for rectifying the output of theamplifier, the amp1ifier rectifiers having input and output terminals,means for connecting the alternating-current windings on one pair ofmagnetic core members to the input terminals of one of the amplifierrectifiers and means for connecting the alternating-current windings onthe other pair of magnetic core members to the input terminals of theother amplifier rectifier, a control winding disposed on each of themagnetic core members, the direction and magnitude of the current fiowthrough the control windings being dependent upon the polarity of theoutput voltage of the network, a biasing winding disposed on each of themagnetic core members, another resistance member connected between anoutput terminal of one of the amplifier rectifiers and output terminalof the other amplifier rectifier, the biasing windings on one pair ofmagnetic core members being connected between one end of the said otherresistance member and an intermediate point thereof, the biasingwindings on the other pair of magnetic core members being connectedbetween said intermediate point cf said other resistance member and itsother end, the biasing windings on one pair of magnetic core membersbeing so disposed that for a predetermined directional output from thenetwork the fiux produced by the current fiow through the biasingwindings is in magnetic opposition to the flux produced by the currentfiow 13 through the control windings on the same pair of magnetic coremembers when the flux produced by the current flow through the biasingwindings disposed on the other pair of magnetic core members is additiveto the flux produced by the current flow through the control windings onsaid other pair of magnetic core members, and control means responsiveto the output of the two amplifier rectifiers for controlling theelectrical quantity.

SCHUYLER L. BRADLEY.

References Cited in the file of this patent UNITED STATES PATENTS N meDate Number 14 Name Date Short Jan. 16, 1945 Rustebakke June 22, 1948Kirshbaum Aug. 24, 1948 Bockman Mar. 15, 1949 Tweedy July 5, 1949 LammAug. 2, 1949 Harder et a1 Sept. 20, 1949 Forssell Apr. 18, 1950 Hedstromet a1. May 30, 1950 Ker Feb. 13, 1951 Sikorra et a1 Apr. 17, 1951

